SpaceX - Falcon 9 Launch This Evening

[JeffKeryk]

Starlink satellites for their high-speed low earth orbit internet constellation.
This is simply amazing. Stage 1 reentry and dead nuts landing is about 8:30 into the flight. For reuse, of course.

To maintain an orbit that is 22,223 miles (35,786 kilometers) above Earth, the satellite must orbit at a speed of about 7,000 mph (11,300 kph).
So cool...

 

[dlundblad]

First time I saw these I thought earth was getting invaded. Lol

 

[Number_35]

Starlink satellites for their high-speed low earth orbit internet constellation.
This is simply amazing. Stage 1 reentry and dead nuts landing is about 8:30 into the flight. For reuse, of course.

To maintain an orbit that is 22,223 miles (35,786 kilometers) above Earth, the satellite must orbit at a speed of about 7,000 mph (11,300 kph).
So cool...

A satellite orbiting 22K miles above the Earth takes 24 hours to complete an orbit, resulting in it being geosynchronous - effectively staying above a single spot.

SF writer Arthur C Clarke proposed the idea in the early 1950s. He figured with three satellites in geosynchronous orbit (spaced 120 degrees apart), you could have worldwide coverage.

 

[Touring5]

A satellite orbiting 22K miles above the Earth takes 24 hours to complete an orbit, resulting in it being geosynchronous - effectively staying above a single spot.

SF writer Arthur C Clarke proposed the idea in the early 1950s. He figured with three satellites in geosynchronous orbit (spaced 120 degrees apart), you could have worldwide coverage.

Hence the "Clark Arc".

(-from an old C-band guy)

 

[Number_35]

Hence the "Clark Arc".

(-from an old C-band guy)

https://spie.org/samples/PM128.pdf

1945! Much earlier than I'd thought.

The 'net turns up arcane references to the Clarke Arc without explaining it. Can you help? Thanks.